<div>
  <div id="arrayList">
    <span v-for="String val in arrayList">{{val}}</span>
  </div>
  <div id="linkedList">
    <span v-for="String val in linkedList">{{val}}</span>
  </div>
  <div id="hashSet">
    <span v-for="String val in hashSet">{{val}}</span>
  </div>
  <div id="hashMap">
    <span v-for="String val in hashMap">{{val}}</span>
  </div>

  <collection-observation-child
      ref="child"
      :arrayList="arrayList"
      :linkedList="linkedList"
      :hashSet="hashSet"
      :hashMap="hashMap"/>
</div>